Screeners for cleaning grain and the like have heretofore been provided which include one or more rotary screens to separate the grain from foreign materials. In one type of screener, inner and outer coaxial drums are provided, each including an annular screen supported by a plurality of axially spaced rims. The grain to be cleaned is supplied into the inner drum to fall through the screen thereof which may have a relatively coarse mesh, coarse foreign materials being retained within the inner drum. The outer drum has a fine mesh screen to allow fine foreign materials to pass therethrough, the grain being collected in the fine mesh screen of the outer drum for removal from one end thereof.
In one type of construction, the coarse foreign materials are removed from one end of the inner drum by passing radially outwardly through a chute which is secured to the inside of the screen of the outer drum at a position intermediate the ends thereof. The coarse materials thus are discharged downwardly and may be received in a pan which also receives the fine foreign materials passing through the outer drum. The pan may be provided with an opening in its bottom and suitable auger means for moving the foreign materials to the opening. Drive means are provided for rotating the drums in opposite directions and in one type of construction, a pulley is connected through a shaft to the inner drum and is driven through a belt from a shaft which extends longitudinally alongside the drums, the shaft being driven by a motor and being also arranged to drive another belt to drive a pulley which is connected to the outer drum at the opposite end.